a~ AMERICAN ACADEMY~ OF OPHTHALMOLOGY

Th. Ey. M.D. Association

Light rays enter the eye through the clear cornea,pupil and lens. These light rays are focused directlyonto the retina, the light-sensitive tissue lining theback of the eye. The retina converts light rays intoimpulses that are sent through the optic nerve to yourbrain, where they are recognized as images.

REFRACTIVE ERROR

The eye's ability to refract or focus light sharply onthe retina may be affected by avariety of conditions.When the eyeball is too long, visual images arefocused in front of the retina, and myopia, or near-sightedness, results. When the eye is too short, imagesare focused beyond the retina. This causes hyperopia,or farsightedness. If the cornea is not perfectly round,then the image is refracted or focused irregularly,resulting in a condition called astigmatism. Similarly,an irregularly-shaped natural lens or problemswith the way it functions also can cause focusingproblems. These various focusing problems can causelight rays to bend or refract at odd angles, leadingto blurry or distorted vision. This inability to achievesharp focus is called refractive error.

There are a number of methods used to correctrefractive errors, including eyeglasses, contact lenses,and refractive surgery.

___ Pupil__Iris

WHAT IS PHOTOREFRACTIVEKERATECTOMY?

Photorefractive keratectomy (PRK) is an out-patient surgical procedure used by ophthalmologists(Eye MD.S) to treat myopia, hyperopia andastigmatism. With PRK, an excimer laser is used tosculpt the cornea, permanently changing its shape toimprove the way the eye focuses light onto the retina.

AM I A GOOD CANDIDATE FOR PRK?

TO be a candidate for PRK, you must have a stable andappropriate refractive error, be free of eye disease,be at least 18 years old, and be willing to accept thepotential risks, complications, and side effects of PRK.You should not have a significant skin or systemicdisease that could affect healing. You should also nothave a history of excessive scarring. If you meet theserequirements, PRK may be appropriate for you tocorrect your refractive error.

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